Cutter chain



Oct. 26, 1937.

w. J.. BERTOVICH CUTTER CHAIN A INVENTOR Filed March 15, 1936 Patented Oct. 26, 1937 UNITED STATES CUTTER CHAIN Wesley J. Bertovich, Wilkinsburg, Pa., assignor of one-half to William H. Schoen, Jr., Pittsburgh,

5 Claims.

My invention relates to cutter-chains, and consists in a cutter-chain structure which is particularly, although not exclusively, adapted for use in coal-mining machinery.

A cutter-chain of the'usual sortconsists in an endless series of pivotally interconnected links carryingpointed cutter-bits. The usual mining machine includes means for driving the cutterchain, in such manner that the travelling bits are'caused to cut a kerf in the base of the body of coal to be removed. As the operation continues, the travelling chain is advanced into the body of coal, until an undercut of desired depth has been made. Then the machine is withdrawn, and the undercut body of coal removed in usual way,

In service the cutter-bits become dull in a rela- V tively short time, necessitating the introduction of newly pointed bits, and the resharpening or renewal of those removed. So far as economy will permit, operators have resorted to hard steel alloys for the bits, but full satisfaction has never been realized. n

More specifically my invention consists in the particularly effective organization of pointed spur-wheels in a cutter-chain, to the end that the usual cutter-bits may either be entirely elim-' inated, or (if cutter-bits be used in association withmy structure) their serviceability increased. As appears in the following specification, the invention also embraces many refinements and elaborations in detail.

A cutter-chain embodying theinvention is illustrated in the accompanying drawing, in which Fig. I is a fragmentary view of the chain in sideelevation; Fig. II is a fragmentary View of the same in plan from above; Fig. III is a view to larger scale, showing infront elevation one of the spur-wheels of the chain structure; Fig. IV is a view of the same, partly in side elevation and.

partly in vertical section; Fig. V is a view, comparable with Fig. III, of a modified spur-wheel embodied in the structure; and Fig. VI is a view in side elevation of the same; Fig. VII is a sectional view of the chain structure, taken on the I plane VII-V1I of Fig. I, and shown to larger scale; and Figs. VIII and IX are similar views of the chain structure, taken on the planes VIII--VIII and IX-IX of Fig. I, respectively.

Referring to the drawing, my cutter-chain consists in a series of tool-carrying links I, pivotally interconnected in known way by paired straplinks 2, 2, and providing an endless or closed chain (only a portion of the complete chain is shown) for service in a mining machine. The

Application March 13, 1936, Serial No. 68,631

sprockets on the usual driving wheel of such ma chine enter the openings 3 between successive links I and the strap-links 2, 2, and the opposite ends of links'l are rounded, as shown at la, for cooperation in usual way with the sprockets.

It will be understood that the endless chain, as

embodied in the mining machine, extends out- 1 Ward in opposite reaches from the driving wheel, and passesaround the periphery of a semi-circular supporting head. Between the driving wheel and the head, sturdy rails are provided for supporting and guiding the intervening reaches of the chain. The links [are providedwith'body portions lb which, in chains of usual construction, are formed to carry pointed cutter-bits; in normal operation of the mining machine, the driving wheel is powerfully rotated; the chain is thereby caused to travel along the guiding rails and around the supporting head; and the ma-' chine is provided with means for progressively advancing the chain-supports in such manner that the travelling chain is fed into the body of coal being mined, and the pointed bits carried thereby are caused to cut a kerf in such body.

In accordance with my invention, I form the body portions .lb' of the links I as bearings, and rotatably mount pointed spurwheels 4 thereon.

Advantageously, each bearing (lb) carries twospurwheels in spaced-apart relation, and, as shown inFig. VII, 2, heavy journal 5 affords the immediate mounting. A threaded stem 50!. is pro-;

vided at each end of the journal 5, and. such stems are of smaller diameter than the intervening body of the journal, thus. providing shoulders 5b. The spur-wheels 4 are centrally bored and threaded, and are secured on the threaded stems 5a tight against the shoulders 5b of the journal.

The interval between the shoulders is slightly greater than the interval between the opposite side faces Id of the bearing, and thus provision is made foripositively preventing undue frictional engagement of the wheels against the side faces of the bearing. 7

.It will be observed that the stems are threaded in opposite direction, so that in service there is no tendency for the spur-wheels to unscrew and become loose.

In the operation of a mining machine embodying my structure, the points la oi the spur-wheels carried by the traveling chain l, 2 are brought to bear, throughout a portion of the endless ohains ambit, against the face of the coal vein to be undercut. In this effective portion of the chains ambit, the points of the spurs 4a are pressed into the exposed body of coal, and, as the chain travels,

the chain as a whole may be likened to a myriad.

of miners picks applied continuously. Thus, the continuously traveling chain picks its way into the body of coal and provides the desired kerf or undercut. During such operation, the brokenout fragments of coal, sometimes called the slack, are by the bodies of the bearings lb swept from the kerf and prevented from interfering with the action of the pointed spurs. 7 It has been found that wear on the points of the spur-wheels is very much less than the wear on the points of the usual cutter-bits, and it appears thatgood results may be obtained with spur-wheels whose points are dulled to a degree which renders cutter-bits unfit for service. And my spur-wheel chain operates with a speed 'comparing favorably with the speed of cutter-bit chains. Accordingly, substantial economies in the maintenance and operation of coal-cutting machines are realized.

Returning to a consideration of detail, it will be understood that my structure embodies many features of inventive moment. The spur-wheels 4 are of such simplified form that they may be readily and economically manufactured in a drop-forging operation. In Figs, II and IV, it will be perceived that the radiating spurs 4a of the wheels 4 include side faces 40 that are, advantageously, inclined laterally to the plane of wheel rotation. That is to say, the radial bodies of the spurs 4a are inclined to a plane P-P (Fig. IV) lying normal to the axis of thewheel and extending medially through the bases of the spurs, and the outer tips or points of the spurs are offset from such plane by an interval 2. Thus it is that a pair of spur-wheels may be mounted upon a bearing lb with their spurs inclined outward, as shown in Fig. VII. The interval a between the points of the two spur-wheels defines the kerfcutting spread or width of the chain (note the bearing lb furthest to the left in Fig. II). The next succeeding bearing (lb) in the chain is identical in width with the bearing lb, but the spread b defined by the points of its spur-wheels is less than a. The result is gained merely by reversing the positions of the spur-wheels, so that their spurs are inclined inward, as shown. in Fig. VIII. It will be seen, therefore, that, while the individual elements of two succeeding links I are identical, the cutting spread of one is less than the other. The third and fourth bearings Nb) of the chain are made of less width than the first and second, and the spur-wheels 4 are mounted with their teeth inclined outward on one and inward on the other, thereby obtaining spreads c and d, each unequal to the others in value. Thus, it will be understood that the groups of spurs carried by the wheels 4, are staggered longitudinally of the chain. And in this case the staggering of the spurs is obtained, first, by mounting on each link l two spur-wheels spaced apart transversely of the chain, and, second, by varying such transverse spacing of the wheels on succeeding links. The spread a of the first link of the group, being greatest of all,

I will sufiice.

extending kerfs.

defines the width of kerf cut by thechain, and the spur-wheels of the three next succeeding links are of lesser and unequal spreads, The fifth link in the series carries two flat spur-wheels 4!! 0f the unspecialized shape shown in Figs. V and VI, and the bearing llib is, as shown in Fig. IX, of bifurcated structure, to permit the two wheels 4!) to be rotatably mounted on a pin El} in the closely spaced relation illustrated, providing a spread e which is narrowest of all.

The next group of links is a substantial duplicate of the group just described, and the illustration of the first link of such second group These two groups of links may be repeated, and still other groupings may be interposed, to make up the endless cutter-chain.

It will be seen that, by varying the spacing of the spur-wheels transversely of the chain, I insure against the spur points of one wheel tracking the points of a preceding wheel; that is, the points of one wheel are prevented from registering with the line of pits dug in the coal by a preceding spur-wheel, and thereby retarding or partially zation of links and spur-wheels given herein, I;

provide ten spurs on each of the wheels 4 included with the first group of links I, and eight spurs on each wheel 46!) included with the second group of links I00.

And so the wheels of each group' of links (or of each link for that matter) maybe provided with spurs unlike in number from those on the wheels of another group, (or of another link). Thus, the alignment of particular spurwheels longitudinally of the chain (note the alignment in this case of the wheels on the first link I of group one with the wheels on the first link I08 of group two) may be advantageously employed, without the spur points tracking in the objectionable manner alluded to. a

The cutter-chain of this invention has beenparticularlydeveloped for cutting horizontal kerfs in coal veins, but it will be understood that it may be used in machines for cutting vertically Additionally, it is contemplated that the cutter-chain may be employed elsewhere than in mines and for the cutting of other bodies than coal. And it will be readily apparent to those skilled in the art that various departures from the exemplary structure described above may be made without departing from the invention as defined in the following claims.

I claim. as my invention:

1. A cutter-chain including a series of pivotally interconnected links carrying rotary spur-wheels, the spurs carried by said wheels being spaced apart transversely of the chain. and in staggered reiation longitudinally of the chain, and the spurs on certain of the wheels varying in number from the spurs on others, to prevent precise tracking of the spur points, as described.

2. A cutter-chain including a series of pivotally interconnected links carrying rotary spur-wheels, the spurs on said wheels converging outward from their bases to points and comprising each a frusturn of a rectangular based pyramid, said spurs being adapted, when the chain is in service in a mining machine as described, to operate in effect as a myriad of continuously applied picks. v

3. A cutter-chain including a series of pivotally interconnected links carrying bearings, rotary spur-wheels carried in laterally spaced-apart relation by said bearings and defining a kerf-cut- 15 described, to provide unequal kerf-cutting spreads longitudinally of the chain.

4. The structure of the next preceding claim, in which the spur-wheels on the first-mentioned bearing are identical with the spur-wheels on the second, with the inequality of spread being obtained by reversal of position of the wheels on the first bearing with respect to the second, substantially as described.

5. In a cutter chain for a mining machine, said cutter chain comprising links including each a bearing, a journal in said bearing, two shoulders embodied in said journal and spaced apart axially of said journal a greater interval than the effective axial extent of said bearing, said journals carrying outward of said. shoulders oppositely threaded stems, and spur-Wheels severally secured against said shoulders by threaded engagement with said oppositely threaded stems, substantially as de- 10 scribed.

WESLEY J. BERTOVICH. 

